Gas burner, including primary and secondary air preheater



June 12, 1951 T. A. NISSINEN 8 GAS BURNER, INCLUDING PRIMARY A D SECONDARY AIR PREHEATER Filed Dec. 18,1945

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INVENTOR Jaz'mz A.M1Ssz zen ATTORNEY- Patented June 12, 1951 UNITED STATES P T or-rice .GAS BURnERQ INCLUDING-PRIMARY AND SECONDARY AIR PREHEATER Toimi A. Nissinen, Dobbs Ferry, N. Y. Application December 18, 1945, Serial No. 635,748

,2 Claims. 1

The present invention relates to improvements in gas burners and the like used for heating, and has for its main object the provision of a novel and advantageous form of burner for gaseous material.

Another object of the invention is to provide a novel and advantageous. burner for burning gases mixed with preheated air. Y

Yet another object is to provide a burner .for an air and gas mixture wherein air isheated by the burner itself preparatory to its. admixture with thegas.

A further object of the invention is to provide a burner for an air and gas mixture, having a plurality of parallel ducts provided with burner jets and one of said ducts being used to. .heat a duct supplying air for mixture with the gas.

A still further object of theinvention is to provide a gas burner of the general Character specified, having provisions to prevent backfiring. v p

A yet further object of the inventionis to provide a novel and advantageous burner wherein the temperature maintained adjacent thedischarge jets assures ignition of the air and gas mixture and complete. combustion ,thereof.

According to arpreferred embodiment ofthe invention the burner comprises parallel jettubes closed at one end. and atthe, otherwend connected to the bottom of a mixingchamber.

Above the central jet tube and heated ,by the burning gasesrising therefrom, is an air supply tube supplying air under relatively low pressure to the upper part-of said'mixingchamber. The air is mixed with the gas inthe mixing .chamber and the mixture passes downwardlyand'into the adjacent ends of ,the jet tubes whichare closed at their other ends. The jetsof "the burning gas-andrair mixture projectupwardly from -the central jet tube and impingeon the air supply tube, thereby raising the sameto a high temperature as well as the air flow-ing therethrough.

Above eachjet tube at a side of the central jet tube is a refractory body or bafllewhich may be a half tube of heat resistant material, such asa suitable alloy steel. Said bafile may, advantageously, be made of vanadium steel. I

The jets of flame or burning. gases from the jet tubes'at the sides, strike the refractory bodies and are deflectedagainst'the'air duct over the central jet tube or through the throat between the air duct and the baffles. Due to the general arrangement described, the high portion of the air supply duct and the air therein may be raised to temperatures of the order of 800 F.

(c1. its-'10s) appear uponnonsideration ofsithe following 'detailed description. and or the drawings, inwhich:

Fig. 1 is a sidejelevation partly .insection, illustrating one embodiment .of .the invention;

Fig. 2 is a top planview of.;the device; ofFig; .1;

Fig. 3 is an'endtelevation as seenfrom theright of Fig.1.; H

Fig. 4'is ans-enlarged view of anozzlesuch as used in the outletsof: the jet tubes; .and.

Fig. 5'is.a sectionalview takeniin the .plane of the line 55, of Fig.1.

Referring .to the. drawings, the burner. is.i1lustrated as (comprising. a verticallyarranged mixing chamberlfl, a ;central;.burner or jet .tube. H arranged horizontally and ,connected atone end to the lower part of the mixingchamber, .the other endbeing closed .as by a cap !2. ,At opposite. sides of the central; jet ,tube l'l .are. j.et tubes l3 parallel to tube ll andin thesame horizontal plane. Each of these tubeshaseat its upper side outlet openings in whichxare sccured the lower ends .ofjetinozzles Miround at their lower ends, and flattened at'ther top to provide anoutlet openingin theform of .a'narroiv slit [5 extending longitudinallyof thegtube. Each tube [3 is connected at one end to, the mixing chamber 10 by means including an .elbow -l6,.tand is closed atits other end as by meansof a cap.

Gasis supplied to the mixing chamber ill by means of a tube or duct ll passing downwardly through thetop or top "closure 18 of the .mixing chamber andhaving a perforated downwardly-directedhead-IQ. Airmay besupplied to the mixing chamber It at a relatively lowpressure, by means of a fan 20 supplying-air atlow pressure to-the left end (Fig. '1) of a horizontal air duct or tube "21 beneath the central burner tube I I. From the other end of tube 2 I, the air passes through an elbow 22 into an upright tube 23, and from the upper end of said tube 23 through an elbow 24 to a horizontally arranged upper tube or duct 25 extending above the central burner or jet tube H and discharging the air thus heated into the upper part of the mixing chamber Hi. Due to the arrangement of the outlet slots 55 longitudinally of the burner tube 5 i, the duct or tube 21 will be heated substantially uniformly throughout its length. Thus the air is hot when it enters the mixing chamber and higher heating efficiency is attained than would be by mixing cold air with the gas and cooling the flame as heretofore.

In order to utilize the heat from the burner to greater advantage, provision may be made for refractory members or bodies against which the frames or jets of burning gases from the burner or jet tubes i3 impinge. Preferably, said refractory bodies which serve as bafiies are in the form of half tubes 2% which may be made of a suitable heat-resisting alloy such as vanadium steel. The half tubes 26 may be supported from the base or from the other tubes by any well known means. In impinging against the bafiies 26, the jets of flame or burning gases are deflected and a part thereof impinges against the overhead air pipe 25 and acts to heat the air therein and the burning gases are directed through the throat between the air duct 25 and the battles. It will be evident that the air in pipe 25 would be heated even if the central burner tube H were omitted. However, with the heating of the air by both the central burner tube 5 i and the other burner tubes it, very efiicient resuits may be attained.

While it is possible to secure good results by supplying all of the pre-heated air for combustion through the jet tubes, it is preferable to supply only some of the air through the jet tubes and to supply pre-heated secondary air to the burning gas mixture adjacent the jet nozzles. Such secondary pre-heated air is preferably taken from the air heating duct 25 through holes or nozzles Zl so located and directed as to discharge pre-heated air into the zone of initial combustion just beyond the nozzles M. The secondary air induces considerable turbulence which mixes the gases and results in practically complete combustion. By taking both primary and secondary air from the same duct they can be controlled simultaneously and in proper relation to the gas flow.

The intimate mixture of gas and air, with consequent increase in completeness of combustion, is greatly enhanced by the arrangement of the bafiles relatively to the gas and air outlets. The secondary air discharging into the zone of the jets, coupled with the deflection of the gases by the deflectors 26, causes turbulence and directs the mixture not only toward the air duct 25 to assure preheated air, but also through the threats formed by the baflles and the duct 25. The bafiies are soon raised to the kindling temperature of the gas mixture, thus further assuring a high degree of completeness of combustion.

The apparatus herein disclosed attains much greater efficiency than heretofore and gives not only a hotter flame but also substantially perfect combustion.

An important advantage in using the alloy steel half tubes 26 as the refractory members or baffles is that they heat up rapidly and therefore avoid,

at the beginning of a heating operation, the chilling of the jets of flame and incomplete combustion which would otherwise occur, and the consequent falling-01f of efficiency in heating. The baffles 26 very quickly become hot and assure combustion of the gas mixture impinging thereon.

Even if the low pressure blower 20 were omitted, the burner would function and the action would be more or less like that of a Bunsen burner, with the advantages, however, of pre heated air.

It should be understood that various changes may be made and that various features may be used without others, without departing from the true scope and spirit of the invention.

I claim:

In a gas burner, a burner conduit including generally upwardly directed gas jets, an air conduit connected to said burner conduit for conducting primary air to said burner conduit for mixing with gas therein, said air conduit being positioned generally above and to one side of said gas jets, refractory baffle means immediately adjacent said jets and having a deflecting surface inclined to intercept burning gases from said jets and to deflect them toward said air conduit, said air conduit being adjacent but slightly spaced from said bafile means so as to define a throat between said air conduit and said baffle means, said air conduit having openings positioned to discharge preheated secondary air toward said throat and into the burning zone of burning gas from said jet.

2. Agas burner comprising a mixing chamber, a horizontally extending burner tube connected at one end to said mixing chamber, means for supplying air to said mixing chamber including an air supply pipe connected thereto and located above the level of and parallel to said burner tube, means for supplying gas to said mixing chamber, said burner tube having burner outlets along the top thereof, and a baflie located above said burner outlets and positioned to direct flames from said burner outlets onto said air supply pipe for heating air therein whereby preheated air may be supplied to said mixing chambers, said air supply pipe having a plurality of air outlets along the under side thereof for supplying secondary air to the gas from said burner outlets of said burner tube.

TOIMI A. NISSINEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 286,301 Hequembourg Oct. 9, 1883 1,131,916 Day Mar. 16, 1915 1,144,784 Rector June 29, 1915 1,394,073 Evans et al Oct. 18, 1921 1,394,721 Festa Oct. 25, 1921 1,849,236 Killam Mar. 15, 1932 2,131,701 Achterfeldt Sept. 27, 1938 FOREIGN PATENTS Number Country Date 9,745 Great Britain of 1900 

